Control for a fluid operated hammer



June 30, 1959 L. R. CARLTON 2,892,449

CONTROL FOR A FLUID OPERATED HAMMER Filed April 18, 1957 5 Sheets-Sheet 1 mveu'ron LYNN R. CARLTON June 30, 1959 R. CARLTON I 2,892,449

CONTROL FOR A FLUID OPERATED HAMMER Filed April 18, 1957 5 Sheets-Sheet 2 IO O Q f I g 5' [E71 r m I :3 F:

/ u. z n q T 7 is F MA JW June 30, 1959 Filed April 18, 1957 R. CARL-TON CONTROL FOR AFL-UID OPERATED HAMMER 5 Sheeis-Shet 3 INVENTOR. LYNN R. unuou ATTORNEY June 30, 1959 L. R. CARLTON CONTROL FOR A FLUID OPERATED HAMMER 5 Sheets-Sheet 4 Filed April 18, 1957 FIG 6 INVENTOR.

LYNN R. CARLTON June 30, 1959 I R. CARLTON CONTROL FOR A FLUID OPERATED HAMMER Filed April 18, 195? s'she'e zs-sheet 5 FIG 1 INVENTOR.

- LYNN R. CARLTON 2,892,449 Fatenteddune 30,1959

2,892,449 CoNrRo FOR A FLUID ornnarnn rmsnvnn Lynn R. Carlton, Erie, Pa, a'ssignor to Eric Foundry Company, Erie, Pa., a corporation of Pennsylvania Application April 18, 1957, SerialNo. 653,654 9 claims. or. 121-30 In hammers of this general type made according to I previous designs, it was difiicult to control the height variably in which the ram "was raised above the anvil ofthe hammer and, therefore, the force delivered by any particular blow of the hammer.

."Ihe present invention contemplates a hammer with an air, steam, or other fluid actuatedpiston for raising the ram above the anvil thereof after each'downward 'ex cursion thereof. While air and/or steam are included in this discussion as the operating medium, any other fluids, including gases and even liquids, are within the scope of this invention. i A control is provided for admitting air or steam'to the space under the piston which will control the height to which the ramrises above the anvil. The action of the ram is controlled by air or steam supplied to the air or steam actuated piston by a main operating val'vepiston in turncontrolled by air supplied to it by a three way valve which has two throttles. One throttle controls the input to the three way valve and one throttle controls the exhaust from the three way" valve. The point of pick-up of the ram must be set relatively to the height of the dies used. This is controlled by a manually adjusted lever which determines'the amount of air entering the'three way valve which in turn varies the ratei'of travel of the main operating'valve and the'timing ofthe pickup of the ram at the point of rebound at the. bottomof each stroke. -"I'h'e' exhaust from the three .way valve-is controlled by a throttle valve actuated by a foot treadle which controls therate at which air is trol for the ram of. a hammer wherein the control will regulate the rate'of closing of a steam orother fluid valve and, therefore, the rate' at which a ram will rise from' the bottom die.

With the above'and other objects in view, thepresent invention consists of the combination and arrangeme'nt ofparts he'reinaftermore fully described, illustrated in the accompanying drawings and more particularly pointed out in the appended claims, it being under-v stoodthat'chang'es may-be made in the form, size, propbrtions', and'minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention. 1

lnthe drawings: Fig. -1 is a'front View of a drop'hammer according to the invention; r "Fig. 2 is a side view of the drop hammer shown in Fig.1; Fig. 3 is a cross sectional viewtake'n on line 3-3 of Fig/(6;, Fig; 4 is anend view ofthe device shown-inFig. 3;- Fig. 5 is' a'cross'sec'tional View taken on line 5-5 of F Fig. 6 is a side-view ofthe drop hammer according to the invention; and I r Fig. 7 is a schematic piping diagram of the-invention. Now, with more specific reference to the drawings, a drop hammer 19 is shown having 'side frames 11 and 12 supported on an anvil 13' at 14 and15, respectively, with a ram 21 slidably supported therebetween. A piston rod 20 is attached to a piston 23 which slides up and down in a cylinder 24 and the cylinder 24Iis supported on the upper portion'of'a crown 1'7. The crown 17 is supported on'the' side frames -11 and 12 at 18 and 19, respectively. The piston rod 20 is attached to the ram 21 and clamps95 'grip the piston rod- 20 to hold the exhausted from the three way valve and, therefore the 3 rate at which the main operating valve piston 'opens'to exhaust the' air. By slowing down the rateof closingof the main operating piston, air or steam can be admitted under the piston for a longer period of time. Therefore, the'piston by which the ram is raised can be controlled and, consequently, the force of the blow which is struck can be controlled.

It is,-accordingly, an object of this invention toovercome the disadvantages in prior hammers and, m'ore particularly, it is an object of this invention to pi'oi ide a control for a ram stroke of a hammer which is-simple in construction, economical to manufacture, and simple and eificient in operation. h

Another object of this invention isto provide a contr'olfor the ram stroke of a single acting drop hammer; 1 Still another object of the invention is to provide an improved control for'controlling the height at which -a ram of a hammer will rise above the bottom die and, therefore, the force of the blow struck by the ram on thedies. i A further object of this invention is to provide a conram 21'- in its elevated rest position. Guides 22 guide the ram 21 in its up and-down motion between the side frames 1 1 and 12. i

A sow'b'lock 33a is keyed into the' anv'il13 "anda bottom die 110 is tongued to the sow block'33a fAtop die 111 is tonguedto the ram 21. The dies 110 and 111 may have the proper cavities formed therein for-forging the desired article. i

- The clamps are made up of clamp arms 96 each swingably connected to the crown 17 at one end and'they have piston rod disengaging clamp shoes 97 on their distal ends. A clamp releasing cylinder 98 is supported on the crown 117. A clamp release piston 99 is connected through a clamp release lever 100 to a clamp release arm 101'.

The main components of the control are the threeway 'valve 51," a {main operating valve 31, the'cylinder 251, a 'treadle controlled throttling valve 52, and a throttlingvalve 531 ;A main 'operating' valve piston 34 is made' 'up of parts 32 and 33 which are held in assembled relation by a rod 37 havingnuts 35gthreadably engaging it-"andclamping'a washer 316 between the nuts 35 and the piston 34.' The end of the rod 37'is slidably engaged by' a bearing38 to guide the piston 34 in its travel, The upper end of the rod 37 has a nut 40 thereoiij which engages a washer 42. A compression spring 43 is engaged between the piston 34 and the housing of the valve 3i. p l f The main operating valve piston 34 has an elongated peripheral groove 45 therein which overlaps a port 30 when the valve 31 is in closed position and air or steam from below the piston 23 exhausts through a port 47A when the main' valve piston 34 is in the unactu'ated position shown. When the main operating valve piston'34 is in actuated position, it cohnects the port 30 with a port 27. A main operating valve cover 50 contains the threeway valve 51 and the throttling valves 52 and 53 which are shown in Figs. 3, 5, and 7. Air or steam under pressure is supplied to the valve 53 through a pipe 74.

The up motion of the ram 21 is controlled by air or steam from a source of air or steam under pressure which enters the port 27 through the port 30 when the main valve operating piston 34 is forced to the dotted line position 55 shown in Figs. 3 and 7, and the steam entering the port 30 flows into the cylinder 24 through the port 27. Air or steam is supplied to a space 26 in the cylinder 24 below the piston 23 from the port 30 through the main operating valve 31 and the port 27 to the space 26.

Links 62 and 63 and the frame 11 form a parallelogram linkage. When the ram 21 is travelling upward, a cam surface 60 formed on the ram 21 will engage a roller 61 and cause the link 62 to swing upward on parallel links 63 to the position shown, pushing a valve piston 56 upward to align a port 158 with a port 64. Thus, air can exhaust through the throttling valve 52. When the ram 21 drops, the cam surface 60 will disengage the roller 61 and allow the link 62 and the three-way valve piston 56 to move down, connecting a port 7 to the port 158. When the ram 21 of the hammer 10 is at rest, the piston rod 20 and the ram 21 attached thereto will be supported by the clamps 95 which will clamp the piston rod 20 in place.

To start the ram 21, a foot treadle 71 is depressed. The foot treadle 71 is connected to the valve 52 by means of a linkage 70. The depression of the foot treadle 71 opens a pilot valve 104 and allows air to flow through a line 105 to the clamp releasing cylinder 98. The air pressure in the clamp releasing cylinder 98 forces the piston 99 down and rocks the release lever 190 about its pivot 106. The release lever 100 pushes the clamp release am 101 up, swinging the clamp arm 96 up to move the clamp shoes 97 out of engagement with the piston rod 20. The ram 21 will fall due to the force of gravity. As the ram 21 falls, the cam surface 60 will pass the roller 61. The link 62 will fall away from the frame 11 toward the ram 21, pulling the three-way valve piston 56 down to align the port 7 with the port 158 This will allow air to enter a space 58 and force the piston 34 against the force of the spring 43 to the dotted line position 55. This will allow air or steam to flow from the port 30 to the port 27 into the cylinder 24 and raise the ram 21.

The valve 53 may be adjusted to throttle the air flowing from the port 7 to the port 158 and thus, depending upon its setting, to delay or advance the opening of the main valve piston 34. This will also determine the point at which the air or steam begins to enter the cylinder 24. Therefore, pick-up of the ram will be controlled. H

When the ram 21 strikes the die, it will bounce or rebound. The control disclosed herein will enable the operator to adjust the point at which the air or steam begins to be admitted to the cylinder 24 during the point of rebound so that the rebound of the ram 21 actually aids the piston 23 in starting the ram 21 on the upward part of its stroke.

Steam pressure in the cylinder 24 against the piston 23 will continue to raise the ram 21 and as it continues to rise, the roller 61 will engage the cam surface 60, forcing the link 62 with the three-way valve piston 56 to the position shown. This will connect the port 158 with the port 64 and allow air from the space 58 in the cylinder 34 to exhaust through the port 64 and the valve 52.

If the treadle 71 has been released, the ram 21 will move to the top of its path and the clamps v95 will engage the piston rod 20 since air pressure will have been cut off from the clamp cylinder 98 by releasing the treadle 71. If the operator has held the treadle 71 depressed, as the three-way valve piston 56 is moved to the position shown by the rising ram 21, ai ill i wi.

ately begin to exhaust through the treadle controlled valve 52 and as soon as the pressure therein has decreased sufliciently for the spring 43 to overcome the pressure thereof, the main valve piston 34 will move to the position shown, allowing air or steam from the cylinder 24 to exhaust through the port 47A. This will reduce the upward force on the ram 21 and allow it to fall by the force of gravity. It is therefore apparent that reducing the adjustment of the valve 53 delays the opening of the valve 31 and, therefore, the time after the ram 21 reaches the bottom of its stroke before the main valve piston 34 will open.

Reducing the adjustment of the valve 52 by increased pressure on the treadle 71 will allow the space 58 of the valve 31 to exhaust slower and, therefore, increase the time that steam or air is applied to the cylinder 24 and, consequently, increase the height to which the ram 21 will rise before it falls. For repetitive strokes, the treadle 71 can be held down. This will keep air pressure on the clamp cylinder 98 and, therefore, hold the clamps 95 open. Several holes may be provided on the link 62 so that the roller 61 can be adjusted up or down thereon to compensate for the main line fluid pressure supplied. For higher air or steam pressure, the roller 61 will be lowered.

A handle 81 is attached through a lock and a link 83 to a valve which throttles the air or steam flowing to the port 30 from the source. The handle 81 is preset at a position determined by the pressure of the air or steam at the source to bring it to the port 30 at a near optimum pressure.

The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A hammer comprising a frame, a ram movable in said frame, a first fluid cylinder on said frame having a piston slidable therein, means connecting said ram to said first fluid piston, a first fluid supply, a main operating valve connecting said first fluid supply to said first fluid cylinder when in an actuated position and exhausting said first fluid from said first fluid cylinder when in an unactuated position, means to control said main operating valve to move it to an actuated position, said means comprising a supply of second fluid and a three way valve having an inlet, an outlet, and an exhaust, said outlet of said three-way valve being connected to said main operating valve, means connected to said ram controlling said three-way valve to connect said second fluid through said three-way valve to said exhaust when said ram is moving toward the uppermost position, said three-way valve connecting said main operating valve to said second fluid source when said ram is moving toward its lower position, a throttling valve connected in said exhaust from said three-way valve, and treadle means controlling said throttling valve in said exhaust whereby the exhaust from said three-way valve can be controlled, thereby controlling the rate of closing of said main operating valve whereby the ram stroke is controlled.

2. The hammer recited in claim 1 wherein a throttling valve is connected to said first fluid supply to said threeway valve whereby the time at which said main operating valve is controlled is determined.

3. The hammer recited in claim 2 wherein said main operating valve comprises a piston urged to one position by a spring, said piston having means connecting said first fluid cylinder to an exhaust means when said spring urges said piston to one position, said second fluid from said three-way valve urging said main operating valve piston to a second position connecting said first fluid source to said first fluid cylinder when second fluid pressure from said second fluid pressure source is connected to said main operating valve.

4. The hammer recited in claim 3 wherein said means to control said three-way valve comprises a cam on said ram and means connected to said three-way valve means, said cam actuating follower means connected to said three-way valve when said ram is in a predetermined position in its upward travel.

5. A hammer comprising a frame, a ram movable in said frame, a first fluid cylinder on said frame having a piston slidable therein, means connecting said ram to said first fluid piston, a first fluid supply, a first fluid valve connecting said first fluid supply to said first fluid cylinder when in an actuated position and exhausting said first fluid supply from said first fluid cylinder when in an unactuated position, means to control said first fluid valve to move it to an actuated position, said means to control said first fluid valve comprising a supply of compressed second fluid and a three-way valve having an inlet, an outlet, and an exhaust, said outlet of said threeway valve being connected to said first fluid valve, means connected to said ram controlling said three-way valve to connect said second fluid through said three-way valve to said exhaust when said ram is in its uppermost position, said three-way valve connecting said first fluid valve to said compressed second fluid source when said ram is in its lowermost position, a throttling valve connected in said exhaust from said three-way valve, and treadle means controlling said throttling valve in said exhaust whereby the exhaust from said three-way valve can be controlled, thereby controlling the rate of closing of said first fluid valve whereby the ram stroke is controlled.

6. The hammer recited in claim 5 wherein a throttling valve is connected to said second fluid inlet to said threeway valve whereby the rate of flow through said first fluid valve is controlled.

7. The hammer recited in claim 6 wherein said first fluid valve comprises a piston urged to one position by a spring, said piston having means connecting said first fluid cylinder to an exhaust means when said spring urges said piston to one position, said second fluid from said three-Way valve urging said first fluid valve position to a second position connecting said first fluid source to said first fluid cylinder when pressure from said second fluid pressure source is connected to said first fluid valve.

8. The hammer recited in claim 5 wherein clamping means is provided for said ram to clamp said ram in position at the top of its travel, said clamping means being actuated by means on said treadle.

9. The hammer recited in claim 8 wherein said clamping means comprises levers swingably attached to said frame and having clamping means on the distal end thereof, a clamp cylinder piston having means thereon connected to said levers, and an air supply, said means on said treadle comprising a valve connecting air pressure to said clamp cylinder piston when said treadle is depressed whereby said clamping means is released when said treadle is depressed.

References Cited in the file of this patent UNITED STATES PATENTS 1,924,545 Fitzgerald et a1. Aug. 29, 1933 1,979,733 Damerhell Nov. 6, 1934 2,429,780 Terhune Oct. 28, 1947 2,604,071 Rickrode July 22, 1952 

